Radiation therapy is one of the most common therapy methods for malignant tumours, and most of patients with tumours need radiation therapy clinically. However, radioactive rays inevitably damage surrounding tissues and normal cells while killing tumour cells due to the obvious aggression thereof on human bodies, and poor specific selection function thereof for a tumour cell killing effect, thereby causing a series of systemic and local toxic and side reactions of the bodies; therefore, harms with different degrees are caused to the patients, both psychologically and physically.
The main side effects of radiation therapy comprise: (1) the damages of nasopharynxes, oral mucosae and skins; (2) the radioactive damages of hearts; (3) radioactive pneumonitis; (4) the radioactive damages of bone marrows; and (5) others: radioactive brain damages, radioactive proctitis, bladder damages and the like, wherein the damages of oral and nasal mucosae and skins will occur during the radiation therapy, and the patients will have the diseases of xerostomia and pharyngoxerosis, oral ulcers, skin pigmentation and the like, but some damages will occur within several weeks and even several months after the radiation therapy, for example, radioactive lung damages are divided into an early stage, a medium stage and a later stage. The early stage usually occurs within several weeks after radiation therapy, and is clinically presented as acute radioactive pneumonitis; and the later stage may occur within six months or longer after radiation.
Since radiation therapy brings about great harms to human bodies, modern medical workers are in urgent need of searching a biological agent for resolving the hazards of the radiation therapy and mitigating the pain of the human bodies.
Periplaneta americana is a periplaneta insect of blattidae of insecta pterygota blattaria, commonly known as ‘cockroach’, and only contained in the ‘Sheng Nong's herbal classic’ as a medicine, wherein the periplaneta americana is classified as a medium-grade medicine, called ‘flavour: salty and cold; cure: cold and heat syndrome of blood stasis, accumulation breaking, hypopharynx atresia, and internal cold and childlessness’. ‘Cockroach’ is the common name of the periplaneta americana, first appeared in the ‘Supplement to Compendium of Materia Medica’, and also referred to as Shijiang and Huachong; and there are different names in various places, for example, Touyoupo, Chapozi, Zaomazi, and the like.
In recent years, as the emphasis on research and development of the traditional Chinese medicine resources in China, some scholars researched this injurious insect that cannot be eradicated for thousands of years in the aspect of applications, made gratifying achievements, and explored the positive value of this injurious insect in the traditional significance. A product ‘Kangfuxin solution’ made from a periplaneta americana alcohol extract through purification has a good curative effect on the wound surfaces of burns, scalds and other injuries, and is also capable of resisting inflammation, diminishing swelling, accelerating lesion tissue repair, and enhancing immunity; therefore, the product can be taken orally for treating duodenal ulcer, gastric ulcer and tuberculosis.
According to the modern digestion theory, proteins can only be absorbed by being converted to small molecular peptides through the gastrointestinal tract instead of being absorbed directly into the blood after being taken orally, the micromolecular peptides are mainly peptides containing 2-15 amino acid residues, with relative molecular masses of less than 3000, and the micromolecular peptides have the characteristics of being capable of being absorbed directly by the digestive tract, fast in transport speed, low in energy consumption, not liable to saturate, and the like. Main ingredients in the periplaneta americana alcohol extract further contain proteins, polypeptides and other macromolecular substances in addition to free amino acids, and the protein macromolecules can only play a corresponding role through the conversion of the gastrointestinal tract after being taken orally instead of being absorbed directly into the blood. Therefore, it is urgent for developing a novel periplaneta americana extract, and the main ingredients contained therein are free amino acids, peptides and other micromolecular substances that can be absorbed directly into the blood.
Currently, there is no application of a periplaneta americana medicinal powder and the extract thereof in radiation therapy.